代码编织梦想


        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>javase</artifactId>
            <version>3.3.3</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.3.3</version>
        </dependency>

工具类

import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
/*
* 二维码生成
* */

public class QRCodeUtil {

    public static void main(String[] args) {

        String codeToFile = createCodeToFile("123");
        System.out.println("输出得信息:"+codeToFile);

    }
    private static final Logger log= LoggerFactory.getLogger(QRCodeUtil.class);

    //CODE_WIDTH:二维码宽度,单位像素
    private static final int CODE_WIDTH = 400;
    //CODE_HEIGHT:二维码高度,单位像素
    private static final int CODE_HEIGHT = 400;
    //FRONT_COLOR:二维码前景色,0x000000 表示黑色
    private static final int FRONT_COLOR = 0x000011;
    //BACKGROUND_COLOR:二维码背景色,0xFFFFFF 表示白色
    //演示用 16 进制表示,和前端页面 CSS 的取色是一样的,注意前后景颜色应该对比明显,如常见的黑白
    private static final int BACKGROUND_COLOR = 0xFFFFFF;

    //一般使用这个就可以
    public static String createCodeToFile(String content) {
        try {
            content = content.trim();
            //核心代码-生成二维码
            BufferedImage bufferedImage = getBufferedImage(content);
            String fileName = System.currentTimeMillis()+"";
            String destFileName = System.getProperty("user.dir")+"/static/"+fileName+".png";
            File codeImgFile = new File(destFileName);
            codeImgFile.getParentFile().mkdirs();
            ImageIO.write(bufferedImage, "png", codeImgFile);
            return "/static/"+fileName+".png";
//                log.info("二维码图片生成成功:" + codeImgFile.getPath());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return  "";
    }

    /**
     * 生成二维码并输出到输出流, 通常用于输出到网页上进行显示,输出到网页与输出到磁盘上的文件中,区别在于最后一句 ImageIO.write
     * write(RenderedImage im,String formatName,File output):写到文件中
     * write(RenderedImage im,String formatName,OutputStream output):输出到输出流中
     * @param content  :二维码内容
     * @param outputStream :输出流,比如 HttpServletResponse 的 getOutputStream
     */
    public static void createCodeToOutputStream(String content, OutputStream outputStream) {
        try {
            if (StringUtils.isBlank(content)) {
                return;
            }
            content = content.trim();
            //核心代码-生成二维码
            BufferedImage bufferedImage = getBufferedImage(content);

            //区别就是这一句,输出到输出流中,如果第三个参数是 File,则输出到文件中
            ImageIO.write(bufferedImage, "png", outputStream);

            log.info("二维码图片生成到输出流成功...");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //核心代码-生成二维码
    private static BufferedImage getBufferedImage(String content) throws WriterException {

        //com.google.zxing.EncodeHintType:编码提示类型,枚举类型
        Map<EncodeHintType, Object> hints = new HashMap();

        //EncodeHintType.CHARACTER_SET:设置字符编码类型
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");

        //EncodeHintType.ERROR_CORRECTION:设置误差校正
        //ErrorCorrectionLevel:误差校正等级,L = ~7% correction、M = ~15% correction、Q = ~25% correction、H = ~30% correction
        //不设置时,默认为 L 等级,等级不一样,生成的图案不同,但扫描的结果是一样的
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);

        //EncodeHintType.MARGIN:设置二维码边距,单位像素,值越小,二维码距离四周越近
        hints.put(EncodeHintType.MARGIN, 1);

        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, CODE_WIDTH, CODE_HEIGHT, hints);
        BufferedImage bufferedImage = new BufferedImage(CODE_WIDTH, CODE_HEIGHT, BufferedImage.TYPE_INT_BGR);
        for (int x = 0; x < CODE_WIDTH; x++) {
            for (int y = 0; y < CODE_HEIGHT; y++) {
                bufferedImage.setRGB(x, y, bitMatrix.get(x, y) ? FRONT_COLOR : BACKGROUND_COLOR);
            }
        }
        return bufferedImage;
    }


}

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本文链接:https://blog.csdn.net/qq_40951656/article/details/127995889